• Title/Summary/Keyword: resistance change

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Estimation of Resistance of Smart Harbor Crane Ship (Smart Harbor Crane Ship의 저항 추정)

  • Shin, Hyun-Kyoung;Kim, Min-Su;Jeong, Won-Jin;Ha, Yong-Hwak
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.1
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    • pp.1-5
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    • 2012
  • Recently, with increasing container ships' volume continuously, the conceptual design "Smart Harbor" of newly logistics processing system has been suggested. It is necessary to estimate resistance and horsepower for the selection of an appropriate propulsor at the initial design stage of Smart Harbor. In this study, CFD and the circulating water channel of the University of Ulsan are employed for estimating the resistance of the Smart Harbor Crane Ship with 1/100 scaled model. Two turbulent models are used. One is realizable k-${\varepsilon}$and the other is Reynolds stress turbulence model. In addition, the effects of the change in y+ and the number of meshes are considered during analysing.

Basic Study of Weaving Structure and Durability for Fabric-type ECG Sensor Design (직물형 ECG센서 설계를 위한 제직구조 및 내구성에 대한 기초연구)

  • Ryu, Jong-Woo;Jee, Young-Joo;Kim, Hong-Jae;Yoon, Nam-Sik
    • Textile Coloration and Finishing
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    • v.23 no.3
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    • pp.219-226
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    • 2011
  • Recently, study of functional clothing for vital sensing is focused on improving conductivity and decreasing resistance, in order to enhance the electrocardiogram(ECG) sensing accuracy and obtained stable environmental durability on operation condition. In this study, four ECG fabrics that having different componnt yarns and weaving structures were produced to analyze their environmental durabilities and electric properties under general operation conditions including different physical and chemical stimulation. For outstanding electric properties and physical properties, the optimized ECG sensing fabric should consist of a fabric of 2 up 3 down twill structure containing 210de silver-coated conductive yarns and polyester yarn in warp and weft directions respectively. The selected fabric has $0.11{\Omega}$ which is relative lower resistance than otherwisely produced fabrics under ECG measurement condition. And it has 7% stable resistance changes under 25% strain and repeated strain.

A Study on the Influence of System Quality Characteristics of Mobile Payment Service on Discontinuance Intention (모바일결제서비스의 시스템품질 특성이 이용자 저항의도에 미치는 영향)

  • Choi, Sangmin;Song, Gwangsuk
    • Journal of Korean Society for Quality Management
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    • v.46 no.3
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    • pp.625-640
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    • 2018
  • Purpose: The scale of a market of mobile payment which was insignificant is explosively being improved by development of various communications technology and achieving rapid diffusion of smart phone. According to this phenomenon, new method of financial dealings through a mobile can be seen as a new paradigm that leads to a change of existing payment work and also recognized as an innovation of information technology. Methods: but a study regarding whether the use of mobile payment service takes an important role as an influencial factor is still insufficient. This study was based on the model of innovation resistance by Ram(1987) and established a hypothesis and a model to confirm how four factors (usability, security, economic feasibility, responsiveness) influence to innovation resistance and the intention of discontinuous use. Results: usability, security were found to be significant predictor variables of innovation resistance to use mobile payment system, but economic feasibility, responsiveness were not found to be significant predictor variables. Conclusion: Providing gave a theoretical foundation for future research in that it presents the variables to consider new forms of mobile payment services, the mobile payment services will need to show a differentiated strategy and traditional marketing strategy.

Biochemical Characterization of Adriamycin-Resistance in PC-14 Human Lung Adenocarcinoma Cell Line

  • Yi, Jae-Youn;Hong, Weon-Seon;Son, Young-Sook
    • BMB Reports
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    • v.34 no.1
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    • pp.66-72
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    • 2001
  • To investigate the mechanism of adriamycin (ADM) resistance in the ADM resistant subline PC-14/ADM, we examined the expressions of p-glycoprotein (P-gp), topoisomerase I (Topo I) and II (Topo II), glutathione-S-transferases (GSTs), tissue transglutaminase (t-TG), epidermal growth factor receptor (EGFR), and E-cadherin and the activity of superoxide dismutase (SOD) in PC-14 and PC-14/ADM cells. There was no change in the cellular levels of P-gp, Topo I, Topo II, and the two isoforms of GSTs. However, SOD activity in PC-14/ADM cells was 2.38 fold higher than that in PC-14 cells. A marked induction of the t-TG expression was also observed in PC-14/ADM cells. In addition to those changes, expressions of EGFR and E-cadherin were down regulated in PC-14/ADM cells. Therefore, molecular modifications such as an increase in SOD activity, induction of the t-TG expression, and down regulation of EGFR and E-cadherin expressions may play important roles in PC-14/ADM cells during the development of ADM resistance.

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Enhancement of coke resistance on Ni/MgO-$Al_2O_3$ catalyst in combined $H_2O$ and $CO_2$ reforming of $CH_4$ for the syngas production (합성가스 생산을 위한 복합개질 반응에서 $Ni/MgO-Al_2O_3$ 촉매의 탄소 침적 저항성 향상에 관한 연구)

  • Koo, Kee-Young;Roh, Hyun-Seog;Jung, Un-Ho;Yoon, Wang-Lai
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.727-730
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    • 2009
  • Highly active and stable nano-sized Ni catalysts supported on MgO-$Al_2O_3$ calcined from hydrotalcite-like materials have been successfully developed with a strong metal to support interaction (SMSI) to enhance the coke resistance in combined $H_2O$ and $CO_2$ reforming of $CH_4$ (CSCRM) for syngas ($H_2$/CO=2) production. The change of the surface area and NiO crystallite size with varying the pre-calcination temperature of support and Mgo content was investigated in relation to the coke resistance. As increasing the pre-calcination temperature, the surface area decreases and the metal to support interaction becomes weak. As a consequence, the coke deposition was more severe on catalysts pre-calcined at high temperature. It was concluded that highly dispersed Ni metal in the surface of Ni/MgO-$Al_2O_3$ catalyst (MgO=30 wt%) pre-calcined at $800^{\circ}C$ had a strong metal to support interaction (SMSI) resulting in an increase of coke resistance and high activity.

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Fundamental Research on the Substitution Earthing Electrode for the Foundation of Building (건축물기초의 대용접지극에 관한 기초연구)

  • Kim, Sung-Sam;Kim, Ju-Chan;Koo, Bon-Kook;Koh, Hee-Seog
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.1
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    • pp.71-76
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    • 2006
  • The electrical characteristics of concrete block including a reinforcing rod in the foundation of the housing was fundamentally reviewed. It was tried to apply the substitutional earthing electrode in the foundation of the building. In order to identify the difference in the earthing resistance between mortar block and concrete block model, those models including a reinforcing rod in their inside were prepared and investigated for the earthing resistance. In results, the earthing resistance was largely affected by the block's resistivity compared to the change of resistance in reinforcing rods and the ground resistivity.

Electrical Impedance Response Model of Concrete in Setting Process (응결 과정 콘크리트의 전기 임피던스 응답 해석 모델)

  • Shin, Sung Woo;Hwang, Garam;Lee, Chang Joon
    • Journal of the Korean Society of Safety
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    • v.29 no.5
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    • pp.116-122
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    • 2014
  • Assessment of setting process of concrete is important as it provides useful information to schedule concreting work in construction site. Electrical impedance measurement method, which utilizes the change of electrical resistance of concrete, has been applied to assess setting process of cement-based materials. However, the applicability of the method has been demonstrated only for cement paste and mortar. The main purpose of this research is to develop the electrical impedance based setting process assessment for concrete. To this end, electrical impedance response model for concrete should be developed in advance since it is essential to estimate the electrical resistance of concrete from measured impedance response. The electrical resistance of concrete is a key parameter for the setting process assessment. In this study electrical impedance responses of the concrete in setting process are measured and analyzed. Thereby, an electrical impedance response model of the liquid state concrete is developed and schematically validated.

$^{31}p$ Nuclear Magnetic Resonance Studies of Acetic Acid Inhibition of Ethanol Production by Strains of Zymomonas mobilis

  • Kim, In-Seop;Barrow, Kevin D.;Rogers, Peter L.
    • Journal of Microbiology and Biotechnology
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    • v.13 no.1
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    • pp.90-98
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    • 2003
  • In vivo $^31p$ Nuclear Magnetic Resonance ($^31p$NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis $ZM4/Ac^R$, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds. $ZM4/Ac^R$ showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo $^31p$ NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For $ZM4/Ac^R$, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.

Effect of Enhancers on the Electrical Properties of Skin: The Effect of Azone and Ethanol

  • Oh, Seaung-Youl;Guy, Richard H.
    • Journal of Pharmaceutical Investigation
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    • v.24 no.3
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    • pp.41-47
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    • 1994
  • The effect of Azone and ethanol on the electrical properties of human and hairless mouse skin was studied and the results were compared. The complex electrical impedance was measured as a function of frequency, and resistance and capacitance were determined from Nyquist plot. After the treatment of human-heat separated epidermis with Azone, contrary to the expectation, resistance increased about 60% and it did not change with time. Capacitance also increased; immediately after the treatment, it was about 110% of pretreatment value and it increased further with time. On the other hand, when hairless mouse skin was treated with Azone, marked changes occured; resistance fell almost to the value of bathing medium itself and capacitance increased to about 200% of its pretreatment value. Similar result were obtained when hairless mouse skin was treated with 100% ethanol. The results suggest that there are differences in the strength of barrier properties of stratum corneum (SC) between human and hairless mouse skin. Overall, the results provide further mechanistic insight into ion conduction through the skin and into the role of SC lipids in skin capacitance.

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Study on irradiation effect by $Co^{60}$ to the carbon resistor (탄소저항체에 대한 $Co^{60}$조사효과에 관한 연구)

  • 지철근;조성욱
    • 전기의세계
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    • v.22 no.4
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    • pp.7-10
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    • 1973
  • The characteristics of all the instruments and materials used in atomic industry is changed due to radiation damages by the effects of radiation activities. In this study, when the Carbon Resistor, main element of electrical circuits, is irradiated by Gamma-Ray, variations in its electrical properties have been investigated. The following results are obtained: 1) The resistance value in Carbon Resistor is exponentially increased as the quantity of irradiation by Gamma-Ray is increased, but in case of more than 10$^{6}$ R/hr. of quantity of irradiation it has saturated-state value. 2) The rate of change inrestistance value has been independent on the intensity of Gamma-Ray source when Carbon Resistor is irradiated in the same quantity of irradiation. 3) The resistance value in irradiated Carbon Resistor has not been varied with elapse of time. 4) The more the distance from the Carbon Resistor to the Gamma-Ray source the more greatly the resistance value is decreased and that it has been shown that the more quantity of irradiation by Gamma-Ray, the greater the rate of decrease in resistance value. Through the above results it has been concluded that the measurement values obtained by the high-precision instruments in the radiation field have to be corrected with proper consideration to radiation damages.

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